Although in existence since 1992, the PET Facility is being proposed as a UPCI Shared Facility for the first time in the CCSG application. Occupying approximately 12,000 sq. ft. within the UPMC Presbytarian Hospital, the Facility is well equipped with a medical cyclotron, a large radiochemistry laboratory, and three patient scanning suites, inpatient and outpatient preparation rooms, laboratories for animal experimentation and metabolite analysis, and offices for PET research faculty and staff. PET can provide unique in vivo information about specific molecular pathways in cancer. It has become a valuable tool for molecular imaging approaches by providing unique information about biological processes and specific cellular pathways in vivo. The development of molecular imaging strategies related to cancer and their translation into clinical application has been recognized by the NCI as an important challenge for the future. The specific aims of the Facility are (1) to provide accessible, comprehensive, and state-of-the-art PET imaging services in support of basic and clinical UPCI research program, and (2) to provide guidance in experimental design, development, validation and implementation of methodology and the interpretation of study data. The PET Facility has instrumentation for human PET imaging (including 3 human PET tomographs and a CPS PET/CT scanner), small animal PET imaging (including a Concorde Micorsystems micro-PET P4 scanner), and a radiochemistry lab (including 3 Capintec hot cells and 4 Capintec 'mini-caves') for development of new tracers for cancer-related imaging. It also has a clinical PET center at both the Hillman cancer Center and UPMC Presbyterian, where 1,667 studies were performed in 2001, 2,400 in 2002 and the projected volume for 2003 is over 3,000. The Facility also operates an extensive computer and data processing network. In addition, it also mentors trainees. The Facility has much potential for support of UPCI's research programs, including in radiation treatment planning with the aid of PET/CT, and small animal imaging of tumor models by PET or a combination of PET and CT, with subsequent translation of promising results into clinical applications for cancer diagnosis and for noninvasive monitoring of response to therapy.